Apparatus and process for graphic image transfer

ABSTRACT

A plurality of graphic images, which may be electrophotographically produced and which are removably disposed in alignment longitudinally of a web arranged for movement in a lineal path between supply and take-up stations, are contact transferable in rows to a card which is arranged for movement intermittently transversely of the path of movement of said web.

United States Patent 1191 Tyler 1 1 July 8,1975

[ APPARATUS AND PROCESS FOR GRAPHIC IMAGE TRANSFER [75] Inventor: Len A.Tyler, Evanston, Ill.

[73] Assignee: Bell & Howell Company, Chicago,

[22] Filed: Nov. 8, 1973 [211 Appl. No.: 414,065

Related U.S. Application Data [62] Division of Ser, No, 160,890, July 8,1971, abandoned, which is a division of Ser, No. 695,228, Jan. 2, 1968,Pat. No. 3,612,685.

[52] U.S. Cl. 60/704; (SO/DIG. 2; 9l/36', 91/41; 91/44 [51] Int. Cl.F021) 73/00 [58] Field of Search 91/35, 36, 41, 42, 43, 91/44, 168, 411R; 60/D1G. 2, 374, 407, 484,

[56] References Cited UNITED STATES PATENTS 2,821,172 1/1958 Randall .491/42 2,860,751 11/1958 Seigle 91/36 X 2,924,199 2/1960 Lawson et a1...M 91/42 2,961,015 11/1960 Randa11.... 91/411 R 3,068,650 12/1962Phillips 91/41 Primary Examiner-Edgar W. Geoghegan Attorney, Agent, orFirmRbert A. Walsh Claims, Drawing Figures r+3 185 as I 167 I 7 67 7 2 V177 1? f 7. 2 g 105 ..l .1 113 n r A 3 I l: 11 L l\\ l SHEET PETE TEDJUL 8 ms MON MQQXE kzhtloqwzuq o Q QQ IQRQZ H m AN PMFQNTEDJUL 8 m5SHEET p// MN 8. Q New I I II 1 N BH Q MN NNN m MUN Em a \x 3 A a m lAPPARATUS AND PROCESS FOR GRAPHIC IMAGE TRANSFER This is a division ofapplication Ser. No. 160,890, filed on July 8, 197i, now abandoned,which in turn was a division of patent application Ser. No. 695,228,filed Jan. 2, 1968, now [1.5. Pat. No. 3,612,685.

The present invention relates to graphic records. Particularly theinvention relates to formation of a visual record by image transfer froma first to a second visual image carrier. Specifically the inventionrelates to apparatus and a process for transferring successive alignedgraphic images which may have been electrophotographically formed in aline longitudinally of a web or first carrier onto a second carrier asaplurality of successive rows of images.

A prior but recently developed process in electrophotography enablesproduction of graphic images whose densities and resolutions approachthose which can be achieved through the medium of silver halide films.In accordance with such prior process, particulate of a photoconductiveinsulative layer of an electrophotographic lamination is treated to forma plurality of aligned visible images longitudinally of a metallic layersupported on a flexible film web as it is moved from a supply source toa take-up station. However, the images are not permanently secured tothe web as the particulate is only electrostatically attracted to themetallic layer. In consequence thereof, the web can be considered only atemporary or impermanent image carrier. That is to say, after imageformation, further steps are required to make a permanent graphicrecord.

While various expedients might be conceived for permanently affixing theelectrostatically held images to their web, the product thus producedwould be satisfactory only for some purposes. It would not, however,.bereadily adapted for easy addition of relevant intelligence at or nearany given image. This characteristic is more readily available whenvisual images are carried in successive rows on, for example, cards.

It is an object of the present invention to provide an improved processand apparatus for forming a graphic record.

It is another object of the invention to provide an im proved method andapparatus for contact transfer of graphic images in formation of apermanent record.

It is a further object of the invention to provide an improved graphicrecord in which the images are produced by an electrophotographicprocess.

It is an additional object of the invention to provide a permanentvisual record from particulate comprising a photoconductive insulativelayer of an electrophotographic lamination.

It is moreover an object of the invention to provide a record cardhaving successive rows of images.

It is yet a further object of the invention to transfer images from analigned position on a web to successive rows on a record card and thelike.

The features of the invention by which the foregoing objects areeffected comprise an image transfer station which is provided inapparatus for producing a visual record having a plurality of successiverows of graphic images. First supporting means are arranged for moving afirst carrier with transferable graphic images in a path relative theimage transfer station, and second supporting means enable moving asecond carrier in image-receiving association with and transversely ofthe path of the first carrier at said image transfer station.Image-applying means are provided for transferring the graphic images atthe transfer station and from said first carrier into rows on saidsecond carrier. The images may, but need not, be formed in anelectrophotographic process of the particulate from which aphotoconductive insulative layer of an electrophotographic lamination isfabricated. If they are so formed, the first carrier comprises aconductive layer included in said electrophotographic lamination, andthe graphic images are physically transferred from a single row on thefirst carrier to a plurality of successive rows on said second carrierfor producing a permanent visual record.

The foregoing and other objects, features, and advantages of the presentinvention will become more apparent upon consideration of the followingdescription and appended claims when considered in conjunction with theaccompanying drawings wherein the same reference character or numeralrefers to like or corresponding parts throughout the several views.

On the drawings:

FIG. 1 is a front elevational view of apparatus embodying one form ofthe invention.

FIG. 2 is a view according to the section line 2-2 of FIG. 1.

FIG. 3 is a fragmentary rear elevational view according to the line 33of FIG. 2.

FIG. 4 is a view according to the broken section line 4-4 of FIG. 1.

FIG. 5 is a view according to the section line 5-5 of FIG. 1.

FIG. 6 is a view according to the section line 66 of FIG. 5.

FIG. 7 is a fragmentary view in perspective of a plurality ofswitch-actuating cams for operating said apparatus.

FIG. 8 is an electrical wiring scheme for said apparatus.

FIG. 9 is a cross sectional view of an electrophotographic laminationprior to development and drawn to a scale enlarged from the scale ofFIG. 1.

FIG. 10 is a view similar to FIG. 9, however showing theelectrophotographic lamination following development.

Having reference now more particularly to FIG. 1 and FIG. 2 of thedrawings, a chassis or framework generally designated ll comprises abase 13 from which a from vertical hanger plate 15 projects forrotationally supporting a film takeup reel 17 which defines a takeupstation. With lamination supply means defining a supply station 16, reel17 provides first supporting means for an impermanent, temporary orfirst carrier 19 which is movable in a path longitudinally of the webforming said carrier and relative to an image transfer station generallydesignated 2]. As illustrated in FIG. I0, first carrier 19 providessupport for material defining a graphic or visual image 25 which isadapted for transfer in a manner which will become apparent from ensuingdescription.

In the embodiment of the invention illustrated, image 25 consists of theresidue of particulate or particles after development of aphotoconductive insulative layer 27 of an electrophotographic laminationor sandwich 29 (shown undeveloped in FIG. 9). However, as it will beappreciated, all aspects of the invention are not limited to imageformation in the particular manner described. That is to say, theinvention comprehends 3 graphic image formation by any suitable means,includ ing electrical, mechanical, or chemical techniques.

Nevertheless, as illustrated. electrophotographic lamination 29, priorto development, is introduced from supply station 16 and comprises asoluble thermoplastic removable insulator disposed in a layer 31 betweenphotoconductive insulative layer 27 and a metallic layer 33 of, forexample, aluminum. The latter, together with a flexible web or film 35of. for example, mylar, to one of the opposite faces of which layer 33is bonded, forms first carrier 19 after development. Preferably thephotoconductive insulative layer 27 is composed of selenium particleshaving a dimension of about 0.2 microns. The thermoplastic layer 3] isapproximately 2.() microns thick, and the aluminum layer 33 is about 73percent light transmissive and sufficiently thin so that first carrier19 is flexible. To that end, and to enable storage of lamination 29,prior to development, at supply station 16, and to enable storage ofimage carrier 19 on takeup spool 17, after development, web or film 35is between 0.005-0.007 inch thick.

If image 25 is formed in accordance with the herein describedembodiment, layer 27 is charged statically prior to exposure byemploying a corona technique. For that purpose. layer 33 must begrounded. Thereafter, electrophotographic lamination 29 is exposed in aconventional manner, such as by projection or by contact, to form alatent image in layer 27. Subsequently, layer 3] is removed by dippingthe laminations member 29 into a thermoplastic solvent for washing awaysaid last named layer as well as portions of particulate which arenon-image-forming. Remaining after such washing and after evaporation ofthe solvent from the product removed from the wash, is first carrier 19on layer 33 of which selenium particulate corresponding to the latentimage theretofore produced becomes attached as a physical image, asillustrated in FIG. 10. However, the bonding is weak, and transfer ofimage 25, in a manner which will be described presently, is thereforefacilitated. Moreover, as the aforesaid image formation process permitscreation of a plurality of aligned temporarily held imageslongitudinally of first carrier 19, these images can be applied, inaccordance with the present invention, in successive rows on a second orreceiving card or carrier 37 at image transfer station 2| as firstcarrier 19 is moved toward takeup reel 17 for presenting the thereonsupported images in sequence at said transfer station.

Second carrier 37, which may become a permanent visual record, isreleasably secured on a rotatable drum 39 by suitable clamp means 41(FIG. I). Drum 39 comprises supporting means for moving carrier 37during successive periods into image transfer association with carrier19, and to that end said drum is supported at image transfer station 21and is arranged concentrically of and for co-rotation with a shaft 43,for rotating second carrier 37 adjacent the image-carrying face of web35 into image-receiving aspect at said station about an axis extendingtransversely of the path of first carrier 19.

Drum 39 is also arranged for intermittent linear or axial movement; thatis to say, movement transversely of the path of movement of firstcarrier 19. Transverse or axial drum movement is accomplished throughthe medium of a supporting assembly means comprised of a pair ofhorizontally spaced vertical bearing blocks 45 and 47 in which shaft 43is journalled and which, together with a vertical force transmissionplate 49, are rigidly secured to a carriage SI. The latter is includedin means for relatively moving carriers 19 and 37, and is slidable alongchassis base 13 on a thereto fixed horizontal track 53 which extendstransversely of vertical front hanger plate 15 and a thereto parallelfixed rear hanger plate 55 (FIG. 2).

A motive means or reversible motor 59 is arranged for reversibly drivingdrum 39 through the expedient of a sprocket band 57 which is arranged inoperable association with a pair of sprockets 61 and 63. The former issecured to the shaft of motor 59 and the latter is se cured on shaft 43.The face plate of motor 59 is rigidly secured to an upward extension 65of bearing block 45. Thereby, motor 59 is adapted for movement with drum39 and its supporting assembly.

In the illustrated embodiment, images are pressuretransferred or removedfrom first carrier 19 and applied onto second carrier 37. To effect thetransfer, the image receiving areas of carrier 37 are coated with aconventional material 67, such as a soluble plastic, which is normallyhard but capable of becoming tacky to develop an affinity for the imagematerial sufficient to overcome the force with which the images are heldon first carrier 19. To the end that first carrier 19 may be broughtinto transfer association with successive parts of second carrier 37, anair operated cylinder 69 is supported from front hanger plate 15 by abracket 7] which is proportioned to accommodate vertical reciprocationof reciprocative means, fluid operated member or piston 73 of said aircylinder. An assembly including a roller 75, which is included in saidreciprocative means, is carried on the lower end of said piston, and isarranged so that roller spindle 77 extends transversely of the path ofmovement of first carrier 19. The arrangement is such that thecircumference of roller is disposed adjacent the non-image carrying faceof web 35 to intermittently drive said image-containing face againstsecond carrier 37 as piston 73 reciprocates between a first position inwhich said first and second carriers 19 and 37 are disposed in imageimpinging association for image transfer and a second position in whichimage transfer is prevented.

Constant tension on first carrier 19 which causes its engagement withroller 75 results from torque of tensioning means comprising a takeupmotor 79 which is mounted behind front hanger plate 15 for drivingtakeup reel 17 through a gear train 81 (FIG. 4). In the presentembodiment, however, the takeup torque is insufficient to draw firstcarrier 19 longitudinally of its path. Such movement is effected by thetraction generated by the torque of drum 39 as it rotates and the forcewith which roller 75 impinges first carrier 19 against second carrier37.

To the latter end during which image transfer occurs, air is conductedthrough a conduit 83 (FIG. 3) from its supply source (not shown) througha valved body 85 for controlled flow through a conduit 87 to cylinder 69which comprises means for reciprocating roller 75 into and out oftractional association with carrier 19. A solenoid 89 (FIG. 8) isarranged in body 85 for controlling its valve and accordingly the airpressure in cylinder 69. The air thus delivered forces piston 73downwardly against its normal spring biasing to impel carriers l9 and 37relative one another to effect image transfer by contact of image 25with thereon aligned material 67. The period for which the pistonremains at the limit of its downstroke can be adjusted in accordancewith requirements of the evident variable factors so that a length ofonly a desired segment of first carrier 19 will be impinged againstcarrier 37 at any one downstroke, to permit precision transfer ofthereon supported images. The normal tensioning on first carrier 19caused by takeup reel 17 will insure that carrier 19 will follow theroller 75 when piston 73 retracts.

Operating in synchronization with solenoid 89 is an indexing mechanismgenerally designated 91 (FIG. 2) for moving a member such as drum 39axially intermittently to successive positions in which successiveaxially spaced areas of material 67 are aligned with roller 75 forrotation through station 21. That is to say, after image 25 from asection of first carrier 19 of predetermined length has been transferredto second carrier 37, drum 39 will be moved axially for deliveringsuccessive portions of second carrier 37 into alignment with a followingsegment of first carrier 19 for transfer of a succeeding image thendisposed at station 21, and so on, until a successive number of rows ofimages has been applied to second carrier 37.

Control of the tackiness of material 67 is effected by a solvent 93which is stored at a source in supply means being a reservoir 95 (FIGS.4 and 5). As illustrated in FIG. 2, a trough 97 is constrained formovement with carriage 51 by reason of a mounting assembly 99 whichthrough fasteners 101 secures said trough to bearing block 47. Thereby,a fixed relationship is maintained between drum 39 and said trough intowhich said drum partially extends for rotation in a manner such thatmaterial 67 to which image 25 is being transferred at any given time isdisposed outside of said trough.

Liquid receiving means comprising a conduit 103 transfers solvent 93between reservoir 95 and through 97. At its downstream end, conduit 103is connected to a vaporizing chamber 105 which is mounted below and formovement with the trough. A vent 107 (FIG. 2) enables escape of solventgases from chamber 105 into the trough where material 67 is suitablysoftened by vaporized solvent as drum 39 rotates, to effect imagetransfer.

Heating means comprising an electric heater element 109 is arranged withrespect to chamber 105 for vaporizing therein contained solvent. Toappropriately control the heater element, an adjustable thermal switch113 (FIG. 8) is connected in a heater circuit 111. An indicator light115, which is shown connected in parallel with heater circuit 111 byconductors 117, is mounted in a chassis-supported control panel 119(FIG. 1) for obvious intelligence purposes because it may be deemeddesirable from time to time in order to control the tackiness ofmaterial 67 to disconnect heater element 109 from the power source (Notshown).

Control of delivery of solvent 93 from reservoir 95 is through themedium of solvent metering means generally designated 120 (FIG. 4) whichis in fluid communication with the upstream end portion of conduit 103.Said fluid metering means comprises a valve body or housing 121 which isarranged for intermittent fluid transmission by gravity flow betweensolvent reservoir 95 and conduit 103. It is secured by suitablefasteners 123 to a boss 125 which is fast to chassis 11. Valve housing121 has a tapered seat in which a tapered valve 127 rotationally engagesby means of a compression spring 129 which is arranged about valve stem131 between an end of housing 121 and a bearing assembly 133 which issecured on said valve stem in spaced relationship from an end of saidhousing. Valve 127 is corotational with stem 131 for successively movingeach of a plurality of outwardly opening wells 135 and 137 which areformed in said valve first into solventreceiving condition andthereafter into solventdelivering position. To that end, valve housing121 has a plurality of bores 139 and 141 arranged for registration withwells 135 and 137 as they rotate past said bores. The downstream end ofa delivery duct 143 which projects from reservoir is connected in afluid-tight seal to housing 121 with its lumen in registration with bore139. The upstream end of conduit 103 is connected to housing 121 withits lumen in registration with bore 141. In the present illustration,wells and 137 are spaced in diametric opposition so that while one wellfills from reservoir 95 the other empties into conduit 103.

Means for effecting rotation of valve stem 13], and accordingly valve127, comprises continuously driven motor 145 on the output shaft ofwhich a cam 147 is co-rotationally mounted intermittently to move anormally open micro switch 149 to close a circuit 151 (FIG. 8). A motor153 which rotates at a different rate from motor 145 is arranged to beintermittently energized for rotation by circuit 151. Motor 153 has anoutput shaft 155 which is connected by coupling means 157 to aprojection of valve stem 131 for driving valve 127. It is appreciatedthat the parts are synchronized for delivering sufficient fluid tochamber 105 through the medium of cam 147, the dwell and throw of whichare proportioned so that motor 153 will become energized andde-energized for sufficient periods to insure maintenance of thequantity of fluid delivered to chamber 105 within a pre-selected range.

In the illustrated embodiment, indexing mechanism 91 comprises drivenmeans, here shown as a double acting air cylinder 159 (FIGS. 2 and 4)which is mounted from rear chassis plate 55 with its reciprocativepiston or rod 161 secured by opposed fasteners 163 to plate 49. Rod 161is a driven member which is arranged for moving drum 39 axially thereofand is included in means for relatively moving said carriers 19 and 37.Indexing movement, that is to say movement of carriage 51, from theposition of FIG. 2 to the right thereof, to motivate drum 39 atsuccessive intervals transversely of the path of first carrier 19, iscontrolled by air pressure in cylinder 159 transmitted to one endthereof by air tube 167. The latter is in fluid communication with anair supply source (not shown) through a valved structure 165 which isconnected to air supply tube 169. The valve of structure 165 iscontrolled by a solenoid 171 (FIG. 8) which is arranged for intermittent motivation, as will become presently apparent, to producedrum-advancing pressure. For fine control of indexing movement to insurethat only predetermined successive portions of the second carrier 37 arepresented at image transfer station 21, control means in the form of arack or ratchet 173 is mounted for sliding movement in the rear chassisplate 55 parallel to and together with rod 161. Rigid securance of theforward end portion of said rack and plate 49 by suitable fasteners 175causes such simultaneous movement. The rear portion of rack 173 has aplurality of notches 177 (only two of which have been numbered in FIG.2) which are spaced from each other for moving drum 39 intermit tentlysuccessive distances according to the pitch of said notches. Thereby,only desired portions of second carrier 37 will be presented at imagetransfer station 21. A detent 179 is connected to rear chassis plate 55by a bracket 181 from which said detent is rockably hung for removableselective engagement in said notches for restraining axial movement. Thecondition of the detent is responsive to solenoid 183 from themagnetically retractable arm 185 of which the detent is pivotallyconnected by a link 187 and by means of which the detent may be movedfrom holding position when solenoid 183 is energized.

The apparatus is controlled from a power circuit 189 which is shown witha plug 191 for connection to a power source. A lamp 193 is connected inparallel with the power circuit, and is supported in control panel 119(FIG. 1 Also mounted in the control panel is the manual component of aswitch 195 for connecting motor circuits 197 and 199 with power circuit189, thereby to enable operation of motors 145 and 153 ofsolventmetering means 120. The control-panel-hung manual component of aswitch 201 is arranged to connect a transformer 203 into power circuit189, whereby heater element 109 as well as lamp 115 become energized. Amanual control member ofa switch 205 is also mounted in control panel119. The last switch is arranged to connect the circuit 207 of motor 59to power circuit 189. For reversibly driving said motor, circuit 207 hastwo sets of terminals as shown at 209 and 211 for selectively causingcurrent flow in alternate circuits. The circuit 213 of takeup motor 79is arranged for connection to power circuit 189 through the medium of amanually operated switch 215, the control component of which too ismounted in panel 119. The circuits controlled by switches 195, 201, 205,and 215 are independently operable each from the other and also from acircuit assembly 217 with a manual component which is also mounted inpanel 119.

For the purpose of this description, the apparatus is considered asbeing operative in cycles, each having two phases and during whichcarriage 51 moves from and returns to the position of FIG. 2. During theimage transfer part of the cycle, carriage 51 is motivated in successivesteps to an extreme position to the right from its position of FIG. 2.During the other part of the cycle, carriage 51 is returned.

Solenoid 89 for controlling the flow of air to cylinder 69, solenoid 183for controlling the condition of detent 179, and solenoid 171 whichcontrols air flow through valved structure 165 for projection of rod161, and all of which operate during the image transfer part of thecycle of the apparatus, are arranged in circuit assembly 217 which isconditioned for connection to power circuit 189 when a double throwswitch 219 closes against terminals 221 and 223. For the return part ofthe cycle, switch 219 is closed against a pair of terminals 225 and 227to open circuit assembly 217 and condition a circuit 229 for connectionto power circuit 189.

A solenoid 231 which controls the valve in a valved body 233 (FIG. 3) isarranged to be energized by said circuit 229 for controlling flowthrough said last valved body. A duct 235 is arranged to establish aircommunication through valved body 233 between the forward end ofcylinder 159 and an air duct 237 which connects with an air supplysource (not shown). The arrangement is such that air supplied tocylinder 159 through air duct 237 will cause rod 161 to retract from anextended position, thereby to return carriage 51 and, accordingly, drum39, to about the position of FIG. 2. To prevent carriage 51 from beingoverdriven to the left on its return to the position of FIG. 2, a microswitch 239 (FIGS. 2 and 8) is mounted in a fixed position relative thechassis 11. It is disposed in the path of and adapted to be thrown by alug or boss 241 which is arranged for movement with carriage 51, therebyto open circuit 229.

Operating the apparatus for image transfer requires not only closure ofswitch 219 against terminals 221 and 223, but simultaneous forward driveof motor 59, because a plurality of cams 243, 245 and 247 which areco-rotational with shaft 43 control phenomena in circuit assembly 217through operation of micro switch 249, 251 and 253 (FIG. 7). The lattermembers are mounted in alignment with said cams, respectively, and formovement with carriage 51 by reason of securance by tie rods 256 to ahanger plate 255 which is rigidly secured to said carriage. Theactuating arm of each of micro switches 249, 251 and 253 terminates in acam follower which is normally biased into peripheral engagement withits respective cam.

Micro switch 249 is arranged for connection to ter' minal 223 through aconductor 258 in which solenoid 171 is connected in series. Connectionto terminal 223 is achieved during a protracted period of each cycle ofcam 243 during which micro switch 249 is closed against its terminal257. The circuit thus established is completed to terminal 221 through acircuit wire 273 to which terminal 257 is connected by a circuit wire259. The parts are arranged and proportioned so that when the followerof micro switch 249 engages in the dwell of cam 243, the circuit throughconductor 258 will be broken, solenoid 17] will be de-energized, and airsupply to cylinder 159 through air tube 167 will be interrupted. On theother hand, when the follower of micro switch 249 is engaged against thethrow of cam 243, air pressure tending to project rod 161 to the rightwith respect to FIG. 2 will be introduced into cylinder 159 through airtube 167.

When the follower of micro switch 249 enters the dwell of cam 243,switch 249 will close against a terminal 261. Thereby, during each camcycle, a circuit from terminal 223 to terminal 221 will be completedthrough the solenoid 263 of an alternate action relay for shifting itsswitch 265 from terminal 267 or 269, whichever is then engaged by switch265, to the then disengaged of said terminals. As will hereinafter morefully appear, switch 265 comprises means by which drum 39 advances onlywhen roller is out of tractional engagement with carrier 19. Thecircuits of micro switches 251 and 253, accordingly, alternately will beconditioned for connection to terminal 223 through a circuit wire 217.Completion of the circuit to terminal 221 through micro switch 251 isthrough a conductor 272 arranged between said last switch and circuitwire 273. Completion of the circuit to terminal 221 through micro switch253 is also through circuit wire 273 which is connected to said lastswitch.

Solenoid 183 is serially connected in a conductor 275, the opposite endsof which are connected to a terminal 277 and the aforestated terminal267. Micro switch 251, which is normally in closed condition againstterminal 277, in the present embodiment of the invention, is arrangedfor motivation to open condition by the throw surface of cam 245,thereby to deenergizc solenoid 183 and force detent 179, under itsnormal biasing, toward rack 173. Cams 243 and 245 are arranged andproportioned first for energizing solenoid 183 and withdrawing detent179 from a notch 177 while extending force is applied on the rod 161,and then for releasing said detent prior to release of the extendingforce on rod 161 so that upon such release the detent will drop back onthe rack to be cammed by an engaged of horizontal camming surfaces 285(FIG. 2) into the next succeeding slot and thereby stop advance of drum39 at a predetermined position.

Overdriving of drum 39 to the right from its position of FIG. 2 isprevented when boss 241, heretofore described as fixed for movement withcarriage 51, throws a micro switch 279 (FIGS. 2 and 8) to an openposition, as shown in dotted lines in H0. 8, from its normally closedposition, thereby to break the circuit path to terminal 221 and,accordingly, the circuit for projecting rod 16].

As a result of the foregoing arrangement, solenoid 89 can be energizedonly during alternate cycles of cam 245. Consequently, roller 75 onlythen can be driven into image transfer and moving condition for firstcarrier 19. Moreover, roller 75 will be in operative condition only fora fraction of the period during which relay switch 265, which isincluded in means for alternating movement of carriers 19 and 37, isclosed against terminal 269. Such control is exercised through cam 247which is proportioned for closing switch 253 against a terminal 283 fora continuous fractional portion of the cam cycle for completion of acircuit between terminals 221 and 223 through circuit wire 273. Thiscauses energization of solenoid 89 which is serially connected inconducting means 281 whose opposite ends comprise terminals 283 and 269.

By reason of the foregoing, first carrier 19 is prevented fromdisposition in image transfer association with drum 39 while the drum ismoving axially. Furthermore, even though drum-advancing force is appliedduring each cycle of cam 243, such advancing force is thwarted inalternate cam cycles by detent 179 during which times roller 75 isdriven into image transfer position at station 21.

As many substitutions or changes could be made in the above describedapparatus and process, and as many apparently widely differentembodiments of the invention within the scope of the claims could beconstructed without departing from the scope and spirit thereof, it isintended that all matter contained in the accompanying specificationshall be interpreted as being illustrative and not in a limiting sense.

I claim:

1. An indexing mechanism for intermittently delivering successiveportions of a member to a relatively fixed station and comprising: Arack mounted for movement longitudinally thereof in a first directionfor moving said member intermittently successive distances according tothe pitch of rack notches; driven means for impelling said rack formovement; a detent arranged for selective engagement in said racknotches for holding said member from moving, and means for moving saiddetent from member-holding condition to permit said member to move, andmeans connected to said rack and rotationally supporting said member formovement longitudinally of said rack.

2. An indexing mechanism according to claim 1 characterized by motivemeans for rotating successively delivered portions of said member atsaid station and mounted for movement with said rack.

3. An indexing mechanism according to claim 1 in which said rack has aplurality of surfaces leading into successive rack notches, and havingmeans for releasing said detent after movement from holding conditionfor camming engagement with one of said surfaces while said rack ismoving.

4. An indexing mechanism according to claim 3 in which the means forreleasing said detent comprises an electrical circuit including asolenoid for moving said detent alternately with its release andelectrical means responsive to the condition of said member forenergizing and de-cnergizing said solenoid.

5. An indexing mechanism according to claim 1 characterized by hydraulicmeans for moving said rack in the first direction and in an oppositedirection for commencement of movement in the first direction; valvedmeans arranged for controlling fluid flow to said hydraulic means forselectively moving said rack in said opposite direction, and electricalmeans for controlling the condition of the valved means followingcompletion of movement of said rack in said first direction.

1. An indexing mechanism for intermittently delivering successiveportions of a member to a relatively fixed station and comprising: Arack mounted for movement longitudinally thereof in a first directionfor moving said member intermittently successive distances according tothe pitch of rack notches; driven means for impelling said rack formovement; a detent arranged for selective engagement in said racknotches for holding said member from moving, and means for moving saiddetent from member-holding condition to permit said member to move, andmeans connected to said rack and rotationally supporting said mEmber formovement longitudinally of said rack.
 2. An indexing mechanism accordingto claim 1 characterized by motive means for rotating successivelydelivered portions of said member at said station and mounted formovement with said rack.
 3. An indexing mechanism according to claim 1in which said rack has a plurality of surfaces leading into successiverack notches, and having means for releasing said detent after movementfrom holding condition for camming engagement with one of said surfaceswhile said rack is moving.
 4. An indexing mechanism according to claim 3in which the means for releasing said detent comprises an electricalcircuit including a solenoid for moving said detent alternately with itsrelease and electrical means responsive to the condition of said memberfor energizing and de-energizing said solenoid.
 5. An indexing mechanismaccording to claim 1 characterized by hydraulic means for moving saidrack in the first direction and in an opposite direction forcommencement of movement in the first direction; valved means arrangedfor controlling fluid flow to said hydraulic means for selectivelymoving said rack in said opposite direction, and electrical means forcontrolling the condition of the valved means following completion ofmovement of said rack in said first direction.